Sigmund bergmann



(No Model.)

S. BERGMANN.

TELEPHONE.

No.443,494. Patented Dec. 30, 1890.

W I" 'WEFITOT UNITED STATES PATENT OFFICE.

SIGMUND BERGMANN, OF NE\V YORK, N. Y., ASSIGNOR TO EDYVARD l-I. JOHNSON, OF SAME PLACE.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 443,494, dated December 30, 1890.

Application filed October 26, 1885. Serial No. 180,905. (No model.) I

To all whom it may concern.-

Be it known that I, SIGMUND BERGMANN, of New York city, in the county and State of New York, have invented a certain new and useful Improvement in Electric-Telephone Transmitters, of which the following is a specification.

The object of my invention is to effectively transmit articulate speech by a transmitter employing metal contact-points controlled by the vibrations of a diaphragm against which the sound-waves are projected.

In carrying out my invention I employ two metal rods, one extending from the diaphragm and the other held rigidly and adjustably. At their ends where they meet each rod is preferably provided with a platinum point, and the two platinum points are normally in contact. By employing these rods instead of the ordinary short contactpoints the contacts are prevented from ever separating so far as not to quickly return to their normal position of contact, the weight of the rods being such as not to allow excessive movement, and thus all the soundvibrations are responded to from the normal or closed condition of the circuit. The rods are preferably of steel, and as an additional element to insure the quick return of the contacts I prefer to make each rod a permanent magnet, so that they are constantly attracted toward each other, or only one of the rods may be magnetized, which is equivalent.

My invention is illustrated in .the annexed drawing,which is a view, partly in section and partly in e1evat-ion,of a telephone embodying said invention.

A is the diaphragm, which is a thin metal plate held in a suitable case B, having a mouth-piece O. The diaphragm may, however, be a thin plate of mica or other suitable insulating material. To the center of The other contact-carrying rod D, having platinum point a, is held rigidly in a frame consisting of two side pieces E E and a back piece F. Through F passes an adjusting-screw G, by means of which rod D is adjusted to or from rod D. Side pieces E E are secured to case B by screws 1) b.

The circuit Wires 1 2 are connected to binding-posts c c on the case. From post 0 connection is made, by means of wire 3, with the diaphragm; 0r,if the diaphragm should be of mica or other non-conducting material, this connection is made directly with rod D, as will be well understood. Post 0 is connected by wire 4 with the frame E E. The circuit is then 1 c 3 A D D F E 4 c 2. The contact at ct a is controlled by the movements of the diaphragm, and the rods are of such size and weight that their platinum points will not become so far separated.

by any vibration as not to readily return to contact.

As above stated, I prefer, in order to increase this effect, to make one or both of the rods permanent magnets, as shown by the letters N S at the ends.

What I claim is- 1. In a telephone-transmitter, the combination of a diaphragm consisting of a thin plate, a metal rod attached at one end to the center of said plate, and another metal rod held rigidly and making an end contact with the rod attached to the diaphragm, substantially as set forth.

2. In a telephone-transmitter, the combination, with a diaphragm, of two magnetized steel rods making an end contact controlled by the movement of the diaphragm, substantially as set forth.

3. In a telephone-transmitter, the combination, with a diaphragm, of two metal rods making end contact, each having a platinum point, the contact at said points being c011- trolled by the movement of the diaphragm, substantially as set forth.

4. In a telephone-transmitter, the combination, with a diaphragm, of two magnetized steel rods, each having a platinum point, the

Contact at said points being controlled by the movement of the diaphragm, substantially as I set forth. 4

In :1 telephone'transmittel', the co1nbination, with a diaphragm and a metal rod carried thereby, of a rigid frame and an opposing metal rod carried by said frame, and means for adjusting the same, sulvstantinlly as set forth.

This specification signed and witnessed this IO 23d (lfl T of October 1885.

SIGML'N'D BERGMANN'.

Witnesses:

A. W. KLDDLE, E. (7. RO\VLAND. 

